1. Field of the Invention
The present invention relates to a machine tool including movable covers which have cover structures suitable for clearance of chips produced during the use of the machine tool.
2. Description of the Related Art
In some machine tools for machining workpieces, a working area is covered by a cover called a splash guard to prevent chips produced during the machining of a workpiece from flying out of the machine tool. To prevent the chips from adhering to driving portions of a table, which is disposed in the working area and on which the workpiece is mounted, one ends of telescopic covers are fixed to the table, and other ends thereof are fixed to side surface portions of the splash guard. In such a machine tool, chips may accumulate on the telescopic covers fixed to the table. To solve this problem, Japanese Patent Application Laid-Open Nos. 6-91457 and 11-70438 disclose techniques in which upper surfaces of telescopic covers are inclined and thus made resistant to the accumulation of chips.
However, in the above-described technique disclosed in Japanese Patent Application Laid-Open No. 6-91457, no measure is taken to actively scratch away chips, except that the upper surfaces of the telescopic covers are inclined. Accordingly, chips are not sufficiently cleared from the working area.
Moreover, in the above-described technique disclosed in Japanese Patent Application Laid-Open No. 11-70438, measures are taken to clear chips in a machine of a type in which a table having a workpiece mounted thereon is fixed and in which a column having a spindle is movable. However, no technique for improving clearance of chips in a machine of a type in which a table moves in two directions in a horizontal plane has been disclosed.